A chain-elongated oligophenylenevinylene electrolyte increases microbial membrane stability

• Main Authors: Zhou, Cheng, Chia, Geraldine Wan Ni, Ho, James Chin Shing, Moreland, Alex S., Seviour, Thomas, Liedberg, Bo, Parikh, Atul N., Kjelleberg, Staffan, Hinks, Jamie, Bazan, Guillermo C.
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Chemical engineering; Biofuels; Butanol Tolerance
• Online Access: https://hdl.handle.net/10356/151443
• Institution: Nanyang Technological University

A novel conjugated oligoelectrolyte (COE) material, named S6, is designed to have a lipid-bilayer stabilizing topology afforded by an extended oligophenylenevinylene backbone. S6 intercalates biological membranes acting as a hydrophobic support for glycerophospholipid acyl chains. Indeed, Escherichia coli treated with S6 exhibits a twofold improvement in butanol tolerance, a relevant feature to achieve within the general context of modifying microorganisms used in biofuel production. Filamentous growth, a morphological stress response to butanol toxicity in E. coli, is observed in untreated cells after incubation with 0.9% butanol (v/v), but is mitigated by S6 treatment. Real-time fluorescence imaging using giant unilamellar vesicles reveals the extent to which S6 counters membrane instability. Moreover, S6 also reduces butanol-induced lipopolysaccharide release from the outer membrane to further maintain cell integrity. These findings highlight a deliberate effort in the molecular design of a chain-elongated COE to stabilize microbial membranes against environmental challenges.